Nonlinear optical crystal and manufacturing method thereof

Abstract

A nonlinear optical crystal has a chemical formula Li 2 X 4 TiOSi 4 O 12 , wherein X=K or Rb. The nonlinear optical crystal belongs to tetragonal system with space group P4nc and Z=2. The unit cell parameters of Li 2 K 4 TiOSi 4 O 12 are a=b=11.3336(5) Å, c=5.0017(2) Å; and the unit cell parameters of Li 2 Rb 4 TiOSi 4 O 12 are a=b=11.5038(6) Å, c=5.1435(3) Å. The two crystals are thermally stable and show strong second harmonic generation with high laser damage threshold.

What is claimed is: 
     
       1. A nonlinear optical crystal of a formula Li 2 X 4 TiOSi 4 O 12 , wherein X=K or Rb. 
     
     
       2. A nonlinear optical crystal of a formula Li 2 K 4 TiOSi 4 O 12 , wherein the nonlinear optical crystal belongs to tetragonal system, space group thereof is P4nc, Z=2 and unit cell parameters are a=b=11.3336(5) Å, c=5.0017(2) Å. 
     
     
       3. A nonlinear optical crystal of a formula Li 2 Rb 4 TiOSi 4 O 12 , wherein the nonlinear optical crystal belongs to tetragonal system, space group thereof is P4nc, Z=2 and unit cell parameters are a=b=11.5038(6) Å, c=5.1435(3) Å. 
     
     
       4. A method of manufacturing a nonlinear optical crystal, comprising:
 mixing LiF, XF, TiO 2  and SiO 2  to form a first starting reagent, wherein X=K or Rb; 
 heating the first starting reagent to a first temperature to melt the first starting reagent and undergo a reaction; and 
 cooling down the first starting reagent from the first temperature to a second temperature to crystallize a nonlinear optical material represented by a formula Li 2 X 4 TiOSi 4 O 12 . 
 
     
     
       5. The method for manufacturing the nonlinear optical crystal according to  claim 4 , wherein a molar ratio of Li:K:Ti:Si in the first starting reagent is a:b:1:1-4, wherein a and b are between 10-30. 
     
     
       6. The method for manufacturing the nonlinear optical crystal according to  claim 4 , wherein a molar ratio of Li:Rb:Ti:Si in the first starting reagent is c:d:1:1-4, wherein c and d are between 10-30. 
     
     
       7. The method for manufacturing the nonlinear optical crystal according to  claim 4 , wherein the first temperature is between 650° C. and 900° C., and the second temperature is between 550° C. and 700° C. 
     
     
       8. A method of manufacturing a nonlinear optical crystal, comprising:
 mixing LiOH.H 2 O, KOH, TiO 2 , SiO 2  and H 2 O to form a second starting reagent; 
 heating the second starting reagent to a third temperature to undergo a hydrothermal reaction at the third temperature to form a supersaturated solution comprising Li 2 K 4 TiOSi 4 O 12 ; and 
 cooling down the second starting reagent from the third temperature to a fourth temperature to crystallize a nonlinear optical material represented by a formula Li 2 K 4 TiOSi 4 O 12 . 
 
     
     
       9. The method for manufacturing the nonlinear optical crystal according to  claim 8 , wherein a molar ratio of LiOH.H 2 O:KOH:TiO 2 :SiO 2 :H 2 O in the second starting reagent is 2:10:1:4:10. 
     
     
       10. The method for manufacturing the nonlinear optical crystal according to  claim 8 , wherein the third temperature is between 450° C. and 550° C. and the fourth temperature is between 300° C. and 350° C.